Term
| What are the different classifications of adrenergic drugs? |
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Definition
| Direct acting, indirect acting, and mixed acting |
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Term
| What are the two types of direct acting adrenergic drugs? |
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Definition
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Term
| What are the different types of adrenergic agonists? |
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Definition
| Selective (alpha 1 & 2, beta 1 & 2) and catecholamines |
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Term
| What catecholamines are nonselective adrenergic agonists? |
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Definition
| Epinephrine, norepinephrine, and isoproterenol |
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Term
| What catecholamines are selective adrenergic agonists? |
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Definition
| Dopamine and dobutamine (selective for Beta-1) |
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Term
| What are catecholamines derived from? Features? |
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Definition
| Phenylethylamine with OH groups on position 3 and 4 of the benzene ring, high potency for adrenergic receptors, is rapidly inactivated by COMT and MAO and cannot cross BBB unlike non-catecholamines |
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Term
| What are the general effects of alpha-1 receptors? |
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Definition
| Vasoconstriction, increased peripheral resistance, increased blood pressure, mydriasis, increased closure of internal sphincter of bladder |
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Term
| What are the general effects of alpha-2 receptors? |
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Definition
| Inhibits NorE release, inhibits Ach release, inhibits insulin release |
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Term
| What are the general effects of beta-1 receptors? |
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Definition
| Tachycardia, increased lipolysis, increased myocardial contractility, increased release of renin |
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Term
| What are the general effects of beta-2 receptors? |
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Definition
| Vasodilation, slightly decreased peripheral resistance, bronchodilation, increased muscle and liver glycogenolysis, increased glucagon release, relaxed uterine smooth muscle |
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Term
| Norepinephrine has a higher affinity for what receptor? |
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Definition
|
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Term
| Epinephrine has a higher affinity for which receptors? |
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Definition
| Beta-2 > Beta-1 > alpha receptors |
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Term
| How do epi and norepi effect blood vessels? |
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Definition
| Predominant response is vasoconstriction |
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Term
| What kinds of drugs elicit a stronger baroreflex? |
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Definition
| Drugs that activate alpha receptors in the vasculature. Eg. NE mediated increase in BP causes reflex bradycardia and slowing of conduction |
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Term
| What are the clinical uses for epinephrine? |
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Definition
| Reserved for emergency - cardiac resuscitation, bronchospasm in acute asthma, rapid relief of anaphylaxis, reduces intraocular pressure in open angle glaucoma, prolongs anesthesia, topical hemostatic agent |
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Term
| How should epinephrine be administered? |
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Definition
| Rapid onset and high potency if given through IV or inhalation, cannot be given orally due to rapid inactivation by MAO and COMT in the liver and gut wall |
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Term
| What are some side effects of epinephrine? |
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Definition
| Hypertension, tachycardia, reflex bradycardia, ventricular arrhythmias, tremor, hyperglycemia |
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Term
| What effects do hyperthyroidism, diabetes, and beta blockers have on epinephrine? |
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Definition
| Respectively: Enhances cardiovascular actions, increases required insulin dosage, leaves alpha stimulation unopposed causing an increase in total peripheral resistance and blood pressure |
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Term
| What are the characteristics of dopamine? |
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Definition
| Catecholamine, immediate precursor to Epi and NE, synthesized in the kidney |
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Term
| What effect does dopamine have on beta-1 adrenergic receptors in the CVS? |
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Definition
| Positive ionotropy increases contractility |
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Term
| What effect does dopamine have on vascular D1 receptors? |
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Definition
|
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Term
| What effect does dopamine have on Renal D1 receptors? |
|
Definition
| Inhibits Na+ pump and Na+/H+ exchange in ascending limb and loop of Henle |
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Term
| How is dopamine used clinically? |
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Definition
| Improves cardiac and renal function in critically ill patients with severe congestive heart failure and renal failure, treats cardiogenic and septic shock |
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Term
| What are the characteristics of dobutamine? |
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Definition
| Resembles dopamine structurally, relatively selective for Beta-1 receptors, a mixture of several enantiomers, has ionotropic effects on the heart |
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Term
| How is dobutamine used clinically? |
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Definition
| Short term management of cardiac decompensation after cardiac surgery, in CHF, myocardial infarction, can increase CO and SV without marked increase in HR or BP |
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Term
| Where is oxymetazoline commonly found? |
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Definition
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Term
| What is the mechanism of action of oxymetazoline? |
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Definition
| Non-selective alpha agonist, constricts small arterioles supplying nasal mucosa but can damage the mucosa, desensitizing with chronic use |
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Term
| What selective alpha-1 agonists should you know? |
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Definition
|
|
Term
| What selective alpha-2 agonists should you know? |
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Definition
| Clonidine and apraclonidine |
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Term
| How is phenylephrine used clinically? |
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Definition
| Nasal decongestant, much less damaging than oxymetazoline, also as a mydriatic agent for pupillary dilation without loss of accommodation (unlike atropine), reduces IOP in glaucoma (but better meds exist), can help maintain BP short term |
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Term
| What is the mechanism of action of phenylephrine? |
|
Definition
| Activates alpha-1 adrenergic receptors, causes vasoconstriction of nasal mucosa, contracts the radial muscle to dilate the pupil |
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Term
| How is clonidine used clinically? |
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Definition
| Treatment of hypertension, prepares addicted subjects for withdrawal by preventing increase in sympathetic activity and cravings |
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Term
| What is the mechanism of action of clonidine? |
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Definition
| Partial agonist of alpha-2 receptors, more potent at presynaptic terminal, main effect is to lowers BP by acting at nuclei in the lower brainstem to decrease sympathetic outflow to the heart & to the vasculature |
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Term
| Describe the pharmacokinetics of clonidine |
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Definition
| Crosses the BBB, with IV causes transient hypertension followed by prolonged hypotension, oral route causes hypotension (peaks in 2 hrs), transdermal patch used to reduce CNS effects |
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Term
| What ar ethe side effects of clonidine? |
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Definition
| Dry mouth, sedation, marked bradycardia and sexual dysfunction in some patients, side effects may diminish after a few weeks of therapy |
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Term
| What are the risks of abrupt discontinuation of clonidine after long term therapy? |
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Definition
|
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Term
| What are the characteristics of Apracolonidine (Iopidine)? |
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Definition
| Selective alpha-2 agonist, used topically to reduce IOP in open angle Glaucoma as a part of a 3 part drug treatment: timolol -> iopidine -> pilocarpine. Does not cross the BBB |
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Term
| What is the mechanism of action of aprocolonidine (iopidine)? |
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Definition
| Alpha-2 receptor mediated reduction of aqueous humor production via constriction of blood vessels in the ciliary epithelium |
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Term
| What are some important beta-1 selective agonists? |
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Definition
|
|
Term
| What are some important beta-2 selective agonists? |
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Definition
| ALbuterol, salmetrol, and ritodrine |
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Term
| What are the clinical uses of albuterol (proventil)? |
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Definition
| Symptomatic relief of bronchospasm in asthma and COPD, acts on beta-2 receptors on bronchioles within 15 minutes of inhalation, persists for 2-3hrs |
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Term
| What are the clinical uses of salmeterol (serevent) |
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Definition
| Symptomatic relief of bronchospasm and improves lung function in COPD, also used to treat nocturnal asthma |
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Term
| What is the mechanism of action of salmeterol? |
|
Definition
| Acts on beta-2 receptors on the bronchioles, has some anti-inflammatory properties, has prolonged duration over 12 hrs, onset of inhalation is slow and not suitable for acute asthma attacks |
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Term
| What are the clinical uses of ritodrine? |
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Definition
| Selective beta-2 agonist used specifically as a uterine relaxant, given intravenously to arrest premature labor |
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Term
| What are some side effects of beta-2 agonists? |
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Definition
| Excessive activation of beta receptors outside the lung increases heart rate, causes tremor, decreased plasma potassium concentration due to beta-2 mediated uptake into skeletal muscle, increases plasma glucose concentration via beta-2 mediated glycogenolysis in liver |
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|
Term
| What are the non-selective alpha-1 and alpha-2 antagonists? |
|
Definition
| Phenoxybenzamine and phentolamine |
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|
Term
| What are the selective alpha-1 antagonists? |
|
Definition
|
|
Term
| What are the clinical uses of phenoxybenzamine (dibenzylene)? |
|
Definition
| Treatment of pheochromocytoma |
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|
Term
| What is the mechanism of action of phenoxybenzamine? |
|
Definition
| Irreversible antagonist of alpha receptors, decreases peripheral resistance and preload |
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Term
| What are some side effects of pheochromocytoma? |
|
Definition
| Postural or orthostatic hypotension, reflex tachycardia, and tachycardia due to increased NE release from presynaptic alpha-2 blockade |
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|
Term
| What are some side effects of nonselective alpha antagonists? |
|
Definition
| Orthostatic hypotension, tachycardia, vertigo, and sexual dysfunction |
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|
Term
| What are the clinical uses of prazosin (minipress)? |
|
Definition
| Used to treat essential hypertension, CHF, BPH |
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|
Term
| What is the mechanism of action of prazosin? |
|
Definition
| Blocks alpha I receptors in arteries and veins, decreases peripheral resistance and preload |
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|
Term
| What are some side effects of prazosin? |
|
Definition
| Postureal hpotension and syncope about 30-90 min after first dose (first does phenomena), tendency to retain sodium and water, some sexual dysfunction |
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|
Term
| How is tamsulosin (flomax) used clinically? |
|
Definition
| Symptomatic relief of urethral obstruction in benign prostatic hyperplasia (BPH) |
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|
Term
| What is the mechanism of action of tamsulosin (flomax)? |
|
Definition
| Specifically blocks alpha-1 receptors on trigone, internal sphincter, and prostate smooth muscle |
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|
Term
| What are the non-selective beta antagonists (1st generation) |
|
Definition
| Propranolol, timolol, and sotalol |
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|
Term
| What are the Beta-1 selective antagonists(2nd generation)? |
|
Definition
| Atenolol (tenormin) and Metoprolol |
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Term
| What are the 3rd generation beta antagonists? |
|
Definition
| Labetolol (nonselective beta and alpha-1), carvedilol (nonselective beta and alpha-1), and Nebivolol (Beta-1 selective) |
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Term
| What are some pharmacological characteristics of beta blockers? |
|
Definition
| Intrinsic sympathomimetic activity (Cartelol, Pindolol, and Acebutolol), lipophilicity, membrane stabilizing properties that blocks calcium entry and opens potassium channels |
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|
Term
| Beta blockers are used to treat what cardiovascular pathology? |
|
Definition
| Angina pectoris, myocardial infarction, arrhthmias, CHF, and hypertension |
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|
Term
| What are some non-cardiovascular uses for beta blockers? |
|
Definition
| Glaucoma, thyrotoxicosis, anxiety to control somatic symptoms, migraine prophylaxis |
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|
Term
| What are the clinical uses of propranolol? |
|
Definition
| Treatment of essential hypertension, exercise induced angina, arrhythmias, CHF, MI, thyrotoxicosis, migrain prophylaxis |
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|
Term
| What is the mechanism of action of propranolol? |
|
Definition
| Non-selective beta receptor blocker, lowers BP in hypertensive patients by blocking sympathetic activation of the heart, blocks renin release |
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|
Term
| What is the clinical use for Timolol (timoptic)? |
|
Definition
| Treatment of open agnle Glaucoma via non-specific beta blocker, decreases aqueous humor production by ciliary body |
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|
Term
| What are some side effects of beta blockers? |
|
Definition
| Rebound effects of halted abruptly, non-specific beta blockers in asthma patients due to possible bronchoconstriction, Beta-1 selective atenolol is preferred. 2st ad 2nd generation beta blockers interfere with glucose control and insulin sensitivity, masks symptoms of hypoglycemia in diabetics, may also cause sexual dysfunction |
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Term
| What defines 3rd generation beta antagonists? |
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Definition
| Beta-blockers with addition effects such as vasodilatory effects, anti-oxidant effects, and antiproliferative effects. Clinical trials show decrease in morbidity and mortality |
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|
Term
| What are the clinical uses of Labetolol (trandate)? |
|
Definition
| Treats hypertension and hypertensive emergency via IV |
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|
Term
| What is the mechanism of action of Labetolol? |
|
Definition
| Reduces heart rate and cardiact contractility via beta-1 blockade, reduces peripheral resistance via alpha-1 blockade, direct beta-2 activation causes vasodilation |
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|
Term
| What are the clinical uses of carvedilol? |
|
Definition
| Treats hypertension as well as moderate and severe CHF |
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|
Term
| What is the mechanism of action of carvedilol? |
|
Definition
| Reduces heart rate and cardiac contractility via beta-1 blockade, reduces peripheral resistance via alpha-1 blockade, improves insulin sensitivity, anti-oxidant properties |
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|
Term
| What are the clinical uses of Nebivolol (bystolic)? |
|
Definition
|
|
Term
| What is the mechanism of action of Nebivolol? |
|
Definition
| High beta-1 selectivity, reduces HR and cardiac contractility via b-1 blockade, increases NO, antioxidant, reduces total peripheral resistance while CO is preserved |
|
|
Term
| What kind of drug is Desoxyn? |
|
Definition
|
|
Term
| What kind of drug is Dexedrine? |
|
Definition
|
|
Term
| What kind of drug is Ritalin? |
|
Definition
|
|
Term
| What is the mechanism of action of amphetamines? |
|
Definition
| Increases release of dopamin and other biogenic amines by inhibiting dopamin vesicular transporters, inhibits uptake of biogenic amine neurotransmitters, inhibits MAO |
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|
Term
| What are the clinical uses for amphetamines? |
|
Definition
| Narcolepsy, ADHD, ADD, appetite suppressant. Effective orally and can cross BBB |
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|
Term
| What are the characteristics of ephedrine? |
|
Definition
| Present in many herbal preparations, agonist at all adrenergic receptors, increases DA and NE, effective orally and cross BBB, potent CNS stimulant |
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|
Term
| What are the side effects of sympathomimetics (ephedrine)? |
|
Definition
| Arrhythmias, headache, insomnia, nausea, tremors |
|
|
Term
| What drugs inhibit NE synthesis? |
|
Definition
| Alpha-Methyl-P-tyrosine (Metyrosine) and Methyldopa (Aldomet) |
|
|
Term
| What drugs inhibit catecholamine metabolism? |
|
Definition
| MAO inhibitors (Phenelzine and Tranylcypromine are nonselective, Selegiline selects for MAO-B) and COMT inhibitors (Entacapone and Tolcapone) |
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